And by wireing each lever to a XNOR gate (top left from both panels, top middle from both panels etc etc.) and connecting the outputs from each gate to the door you get this awesome thing. The thing the XNOR gate does is that it checks so the the input from both levers are the same, and if they are the gate sends an ON output signal.
|A||B||A XNOR B|
So you will need 9 XNOR gates to connect all the levers.
Here are the chematics Pez posted on the official forums.
And this is for ONE layer, ie 3 levers.
He's posted 3 videos á 30 seconds on his forum post, but I will make a smaller (probably just a single layer) prototype and make a longer video tutorial of it that will be a little more explaining in it.
Over and out!